JP2001124543A - Method and apparatus for measurement of planarity of thin-sheet material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus, for the measurement of the planarity of a thin-sheet material, in which the thin sheet material such as a semiconductor wafer or the like can be held, without being deformed, always at a definite holding force, even when it is turned at high speed and in which the end edge part in the outer circumference of the thin sheet material can be inserted into, and attached quickly by a holding groove in an extremely small groove depth, even when the thin sheet material is attached. SOLUTION: A thin sheet material 23 is held and turned by a plurality of units 42, for thin-sheet material fixation, which are installed inside a hollow spindle 2. The warpage or the like of the material 23 which is being turned is measured by a pair of displacement meters 3. Every unit 42 comprises a moving part 58, which is supported by a support part 57 via a rotation fulcrum part 54. A holding claw part 50, which holds the material 23, is installed at one end part of the moving part 58. In addition, a counterbalance part 60, in which the mass in both side parts of the part 54 is set to be the same mass, is installed at the other end part of the part 58.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention particularly requires that thickness unevenness and warpage in the surface direction be extremely small, for example, thickness unevenness and warpage in thin materials such as semiconductor manufacturing wafers and magnetic disk substrates. The present invention relates to a method and an apparatus for measuring flatness, which is a degree of occurrence of the above.

[0002]

2. Description of the Related Art A wafer for semiconductor production is made of a thin plate material such as silicon, and photolithography and various fine processing techniques are employed for producing semiconductor elements and electronic circuits on the surface of the wafer. . In processing such a wafer, it is very important to enhance the flatness of the wafer surface. This is because if the flatness of the wafer is inferior, for example, a pattern of a semiconductor element or an electronic circuit is unclearly formed on the surface of the wafer or a pattern is formed on the surface of the wafer due to, for example, defocusing during photolithography. This is because the outline of the printed material becomes unclear.
In particular, in recent years, for the purpose of miniaturizing semiconductors and improving productivity, the size of wafers has been increased from the conventional 8 inches to 12 inches, and the densification of semiconductor elements and electronic circuits has been promoted. With such high density and large size, securing the flatness of the wafer surface has become an even more important problem.

Furthermore, in the semiconductor manufacturing process, various processes are often performed on the entire back surface of the wafer on a very precise flat support surface by means such as vacuum suction. At this time, if the wafer has a shape that is relatively largely deviated from the plane, the wafer cannot be chucked accurately during photolithography or the like, and it becomes impossible to project a pattern of semiconductor elements or circuits onto the wafer surface. Therefore, the wafer is required to have an accurate flatness with very little warpage over the entire wafer. Therefore, in the wafer manufacturing process, it is necessary to accurately and efficiently measure the flatness of the wafer in order to evaluate whether the warpage or the like is within an allowable range for all of the manufactured wafers. .

As a conventional flatness measuring apparatus for a thin plate such as a wafer, there is one shown in FIG. 9 proposed by the present applicant (Japanese Patent Application No. 11-92609). This apparatus holds a disk-shaped wafer W in an upright state in the hollow spindle 2 via three thin plate fixing units 4 provided in an annular hollow spindle 2 in a direct drive motor 1. Thus, the rotation of the hollow spindle 2 causes the wafer W to rotate in the vertical plane. The two surfaces of the rotating wafer W are irradiated with measurement light from a pair (only one is shown) of optical displacement meters 3 disposed at symmetrical positions on both sides of the wafer W, and are irradiated from the surface of the wafer W. The reflected measuring light is received by each optical displacement meter 3. Thus, the optical displacement meter 3 optically measures the distance to the surface of the wafer W or a change in the distance.

[0005] The moving stage 9 is driven by a motor 7 to rotate a ball screw 8 so that the pair of guide rails 1 is driven.
The mounting base 11 is configured to linearly move while sliding to zero, and to mount a pair of optical displacement gauges 3 on opposing surfaces and hold them at predetermined intervals at symmetrical positions with respect to the opposing surface of the wafer W. It is installed on the upper surface of the moving stage 9 and linearly moves integrally with the moving stage 9. As a result, the pair of optical displacement meters 3 is moved radially relative to the rotating wafer W in a direction parallel to the surface thereof, and measures the thickness of the entire surface of the wafer W. A flatness calculating means (not shown) composed of an arithmetic processing unit such as a microcomputer calculates a warp or the like of the wafer W based on a measurement result of the pair of optical displacement meters 3, and calculates the warpage of the wafer W based on the calculation result. The quality is determined.

[0006]

However, the flatness measuring apparatus described above still has a problem which must be solved when it is put to practical use. That is, FIG.
FIG. 4 is a perspective view showing a state where the wafer W is held vertically by the thin plate fixing unit 4. The wafer W is extremely thin, having a thickness of 1 mm or less (generally 0.775 mm), and weighs 120 g.
Therefore, when the wafer W is held horizontally, a measurement error occurs due to generation of distortion due to gravity of the wafer W itself. Therefore, the wafer W has its outer peripheral edges held by the three fixed units 4 provided at equal intervals on the inner peripheral surface 2a of the hollow spindle 2 in a state of standing vertically. The holding width of the outer peripheral edge of the wafer W by the thin plate fixing unit 4 is set to 1 mm or less because it is necessary to measure almost the entire surface of the wafer W. Problems with such a flatness measuring device are that the wafer W cannot always be stably held when measuring with the optical displacement meter 3 while rotating the wafer W at a high speed in a vertical plane, and that an extremely thin wafer W can be The thin plate fixing unit 4
Further, it cannot be mounted quickly, and the problem will be described in detail below.

[0007] The thin plate fixing unit 4 is attached to a support base 12 fixed to the inner peripheral surface of the hollow spindle 2 by approximately L.
One end of a movable chuck arm 13 having a U-shape is rotatably attached to a support shaft 14 as a fulcrum. The other end of the movable chuck arm 13 fits and holds an outer peripheral edge of the wafer W. V-shaped holding groove 17 is formed. The movable chuck arm 13 is rotationally urged in a direction indicated by an arrow in FIG. 1 with the support shaft 14 as a fulcrum by a pressing spring 18 made of, for example, a compression coil spring, and the outer peripheral edge of the movable chuck arm 13 is fitted into the holding groove 17. It is pushed to the state where it was made. The holding groove 17 is set to have a groove depth of about 0.2 mm so that measurement can be performed up to near the outer peripheral end of the wafer W.

In general, two of the three thin plate fixing units 4 (not shown) are provided with a fixed chuck arm having a holding groove having the same shape as that described above, in place of the movable chuck arm 13. The wafer W is the one shown in FIG.
Of the other two by the pressing force of the movable chuck arm 13.
The outer peripheral edge of the location is pressed and held in the holding groove of the fixed chuck arm, and attached vertically. The wafer W for which the flatness measurement has been completed is held by a handling arm (not shown) of an automatic mounting device such as a robot, and then the actuator 1 formed of an air cylinder or the like.
When the movable chuck arm 13 is rotated in the direction opposite to the arrow by the suction operation of 9, the holding by the three thin plate fixing units 4 is released, and the movable arm is removed to the outside of the hollow spindle 2 by the handling arm.

As described above, the wafers W whose slight outer peripheral edges are respectively held in the holding grooves 17 of the movable chuck arm 13 and the fixed chuck arm in the three thin plate fixing units 4 are Since it is necessary to reduce the measurement time as much as possible because of the necessity of 100% inspection, the motor is rotated at a high speed by the direct drive motor 1. At this time, the movable chuck arm 13 receives an external force that tends to rotate in the direction opposite to the arrow in FIG. 10 against the urging force of the pressing spring 18 due to a relatively large centrifugal force generated by high-speed rotation. Retention is reduced. According to the measurement results, when the weight of the movable chuck arm 13 is 30 g, the holding force reaches 300 gf due to the centrifugal force when the rotation speed of the wafer W is 240 rpm. for that reason,
Since only a small portion of the outer peripheral edge is inserted into the holding groove 17 and held on the thin wafer W having a thickness of about 0.775 mm, the movable chuck arm 13 reduces the holding force. Accordingly, distortion occurs. As a result, an error occurs in the measurement result by the optical displacement meter 3, and it becomes impossible to measure the warpage of the wafer W or the like with the above-described high measurement accuracy.

[0010] On the other hand, since the wafer W is subjected to 100% inspection as described above, it is necessary to efficiently measure warpage and the like.
When attaching to the three thin plate fixing units 4, it is generally required that a measuring device that measures with a tact of about 1 minute per sheet be quickly performed within 20 seconds.
When mounting a very thin and fragile wafer W having a thickness of 0.775 mm in less than 20 seconds, an automatic mounting machine such as a robot is employed because it is impossible for a worker to perform the work manually.

When mounting the wafer W, FIG.
In the thin plate fixing unit 4 shown in FIG. 0, the movable chuck arm 13 is held at a position where the holding groove 17 is retracted from the holding position of the wafer W by the suction operation of the actuator 19, and is held by the hand rig arm of the automatic mounting machine. The wafer W carried into the hollow spindle 2 is positioned so as to exactly face each holding groove 17 of the three thin plate fixing units 4 and then the operation of the actuator 19 is released. The movable chuck arm 13 is rotated by the urging force of the pressing spring 18, and the movable chuck arm 13 inserts the outer peripheral edge of the wafer W into the holding groove 17 so that the wafer W is separated into two other thin films. Plate fixing unit 4
The procedure is performed by pressing the holding chuck arm toward the holding groove of each fixed chuck arm.

However, the movable chuck arms 13 and 2
Each holding groove 17 of the fixed chuck arm portion is, as described above,
Since the groove depth is set to a very small value of about 0.2 mm, even if the wafer W itself is accurately positioned at a predetermined position by the automatic mounting machine, if the wafer W itself is slightly warped or the like, the wafer W may be deformed. One of the outer peripheral edges is the holding groove 1
7, the wafer W falls and is broken when the gripping of the wafer W by the handling arm of the automatic mounting machine is released. When the measured wafer W is removed, the wafer W held by the thin plate fixing unit 4 is gripped by the handling arm, so that gripping does not fail.

In view of the above, the present invention has been made in view of the above-mentioned conventional problems, and a thin plate material such as a semiconductor wafer, which is extremely thin and brittle, is not always distorted with a constant holding force even when rotated at a high speed. It can be held, and even when attaching a thin plate to a plurality of thin plate fixing units, the outer peripheral edge of the thin plate can be quickly inserted by securely inserting the outer peripheral edge into the holding groove having an extremely small groove depth. It is an object of the present invention to provide a method and an apparatus for measuring flatness of a thin plate material.

[0014]

In order to achieve the above object, a method for measuring flatness of a thin plate material according to the present invention comprises the steps of: A pair of guide pieces are respectively advanced toward the mounting position from a plurality of thin plate fixing units disposed on the inner peripheral surface of the hollow spindle and brought into contact with one surface and the other surface of the outer peripheral edge of the thin plate, respectively. Thus, by positioning the movable portion having a central portion as a fulcrum in one direction by applying elastic force between the pair of guide pieces, it is positioned at a predetermined position. The outer peripheral edge of the thin plate material is held by the holding claw portion of the movable portion that advances to the second position.After that, a pair of guide pieces are retracted in a direction away from the thin plate material, and the thin plate material is Previous The thin plate rotating means is mounted on the inner peripheral surface of the hollow spindle via a thin plate fixing unit, and drives the thin plate rotating means in a state in which the mass of both sides of the rotating fulcrum portion in the movable portion is kept the same. By rotating the thin plate, the distance to the opposing surface of the thin plate is measured by a pair of displacement sensors arranged at symmetrical positions on both sides of the thin plate, and the measurement position of the pair of displacement sensors is measured. Is scanned in the direction of the radius of rotation of the thin plate material, a distance or a change in distance to the entire surface of the thin plate material is measured by the pair of displacement sensors, and based on each measurement data of the pair of displacement sensors, It is characterized in that thickness unevenness and warpage in the entire surface are calculated.

In this method for measuring the flatness of a thin plate, a pair of guide pieces are advanced toward the mounting position when the thin plate carried into the mounting position in the hollow spindle is held by a plurality of thin plate fixing units. The sheet is brought into contact with both sides of the sheet material, so that even if the sheet material is warped, the pair of guide pieces contact the both sides of the outer peripheral edge of the sheet material so as to eliminate the warp and the like. The shape of the sheet material can be modified, and the outer peripheral edge of the shape-corrected sheet material is held by the holding claws, so that even a very thin sheet material can be reliably held. In addition, the same centrifugal force is applied to the movable portion of the thin plate fixing unit on both sides with respect to the rotation fulcrum when the hollow spindle rotates, and the centrifugal force is applied to rotate the hollow spindle in opposite directions. The centrifugal force on both sides can be canceled each other, and the thin plate material is always held at a plurality of outer peripheral edges with a predetermined holding force even at high speed rotation, so that it is not distorted. Can be measured efficiently with extremely high measurement accuracy.

The apparatus for measuring flatness of a thin plate according to the present invention comprises a thin plate rotating means for rotating the thin plate while holding it in a hollow spindle; and a thin plate rotating means fixed to the inner peripheral surface of the hollow spindle. A plurality of thin plate fixing units that hold the outer peripheral edge, and a pair of displacements that are disposed at symmetrical positions on both sides of the thin plate and measure a distance to the opposing surface of the thin plate or a change in distance, respectively. A sensor, a measurement scanning unit that scans a measurement position of the displacement sensor in a rotational radius direction of the thin plate, and calculates thickness unevenness and warpage over the entire surface of the thin plate based on each measurement data of the pair of displacement sensors. At least one of the thin plate fixing units, a support portion fixed to an inner peripheral surface of the hollow spindle, and a central portion through a rotation fulcrum portion. A movable portion supported by the holding portion and rotatably provided, and a holding claw provided at one end of the movable portion, the holding claw having a holding groove for fitting and holding an outer peripheral edge of the thin plate material An elastic body that rotationally urges the movable portion in a direction in which the holding claw portion is pressed against the thin plate material; and both side portions of the movable fulcrum portion provided at the other end of the movable portion and the movable portion And a counter balance unit set to have the same mass.

In the flatness measuring apparatus for a thin plate, the thin plate fixing unit for holding the thin plate in the hollow spindle includes a thin plate holding portion including a holding claw portion on one end side from a rotation fulcrum in the movable portion. The counterbalance part having the same mass as the mass of the mechanical part is provided at the other end of the movable part, so that the movable part of the thin plate fixing unit is rotated when the hollow spindle rotates. Since the same centrifugal force is applied to both sides of the fulcrum, and the same centrifugal force is applied to rotate the fulcrum in opposite directions, the centrifugal forces on both sides cancel each other. Therefore, even when the hollow spindle is rotated at a high speed for the purpose of efficiently measuring the thin plate material, the holding claw portion is fixed by the elastic body regardless of the action of the centrifugal force generated at the time of the high speed rotation. Is constantly applied without any change, and the outer peripheral edge of the thin plate material is stably held by the holding groove. As a result, even at high speeds, the thin plate material is always held at a plurality of outer peripheral edges with a predetermined holding force and is not distorted, so that the displacement gauge can efficiently measure the warp of the thin plate material with extremely high measurement accuracy. Can be measured.

The thin plate fixing unit according to the present invention comprises a pair of guide pieces disposed close to each other on both sides of the holding claw portion, and the pair of guide pieces are provided at the end portions of the opposing surfaces. When the thin plate material is carried into a predetermined mounting position in the hollow spindle, the thin plate is advanced toward the mounting position prior to the advancement of the holding claw portion to the mounting position, and the thin plate is thinned. It is preferable that the outer peripheral edge portion of the plate is configured to be in contact with one surface and the other surface, respectively.

Accordingly, when the thin plate material to be measured is carried into the mounting position inside the hollow spindle while being gripped by, for example, the handling arm of the robot, first,
A pair of guide pieces are advanced toward the mounting position, and the thin plate material is
Even if there is a warp or the like, the guide piece slides on the guide surface of the protruding guide piece and is guided to contact the inner surface of the guide piece, so that the pair of guide pieces contact both surfaces of the outer peripheral edge portion. Thus, the shape is corrected so as to eliminate the warp or the like. That is, the shape of the thin plate material is modified such that the plurality of outer peripheral edge portions are sandwiched by the pair of guide pieces, and the outer peripheral edge portions accurately face the holding grooves of the respective holding claws. After that, when the holding claw portion advances toward the mounting position of the hollow spindle, the outer peripheral edge of the thin plate material is securely inserted into the holding groove of the holding claw portion, and the thin plate material is inserted into the plurality of holding claw portions. Pinched by Therefore, in this thin plate fixing unit, a very thin thin plate having a thickness of 1 mm or less can be reliably inserted into the holding groove having a groove depth of 1 mm, and the thin plate can be held as in the conventional device. Trouble such as falling due to failure does not occur.

In the above structure, the thin plate fixing unit is configured such that an attachment guide mechanism having a guide piece at one end is arranged close to both sides of a fixing mechanism having a holding claw at one end. Wherein the fixing mechanism comprises a support,
A main body block in which a rotation fulcrum, a movable part and a counter balance part are integrally formed; a holding claw fixed to one end of the movable part; and a holding claw in a direction in which the holding claw is advanced to a mounting position of the sheet material. An elastic body that urges the movable portion to rotate, and a solenoid that rotates the movable portion in a direction in which the holding claw retreats from the mounting position, wherein each of the mounting guide mechanisms is a hollow spindle. A movable portion rotatably supported by the support portion at a central portion via a pivot point, and a movable portion provided at the other end of the movable portion. A guide block fixed to one end of the movable portion, the guide block having a main body block integrally formed with a counterbalance portion set to have the same mass on both sides with respect to the rotation fulcrum portion; The piece is the thin plate A configuration may be provided that includes a solenoid that rotates the movable portion in a direction to advance to the mounting position, and an elastic body that rotationally biases the movable portion in a direction in which the guide piece retracts from the mounting position. .

Thus, the thin plate fixing unit comprises a fixing mechanism for holding the thin plate, and a pair of mounting guide mechanisms arranged on both sides thereof for performing an auxiliary operation for securely holding the thin plate. Despite having the components, each of the mechanism units includes an integral body block having a support unit, a movable unit, a pivot point, and a counter balance unit, so that the number of parts can be reduced as much as possible. And the configuration can be greatly simplified. Also, during the measurement operation while rotating the thin plate, the holding claw receives the urging force of the elastic body due to the non-energization of the solenoid and holds the thin plate, and each guide piece is elastic due to the non-energized state of the solenoid. Under the urging force of the body, it is held at the retracted position separated from the sheet material.
That is, each of the solenoids is de-energized during the measurement operation of the thin plate material so that there is no danger of dust generation. Therefore, the thin plate material to be measured minimizes contamination due to dust adhesion like a semiconductor wafer. When it is necessary to prevent this, a particularly remarkable effect can be obtained.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an apparatus for measuring flatness of a thin plate according to an embodiment embodying the method for measuring flatness of a thin plate according to the present invention. In the figure, the same or substantially the same as those in FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted. The direct drive motor 1 is supported on the upper surface of the device stand 20 by a pair of support legs 21. In the direct drive motor 1, an annular exterior fixing portion 22 is fixed to a pair of support legs 21 and is held at a position above the apparatus base 20, and is a rotatably provided circle inside the exterior fixing portion 22. In the inside of the annular hollow spindle 2, for example, the thin plate material 23 such as the above-mentioned semiconductor wafer W is set up vertically, and the outer peripheral edge thereof is provided with a plurality (usually three) of thin plate fixing units 24. It is fixed and attached.

In the direct drive motor 1, a coil (not shown) is provided on the exterior fixing portion 22, and a magnet (not shown) is provided on the hollow spindle 2 so as to face each other with a predetermined gap. It has a well-known configuration, for example,
Rotational unevenness is extremely small as compared with a case where the rotating body holding the thin plate member 23 is rotationally driven by a rotating power of a general motor via a transmission mechanism such as a belt or a gear. Therefore, this direct drive motor 1 is
It is suitable as a rotation drive source of the flatness measuring device of the embodiment for measuring the warpage or the like with high accuracy while rotating.

The thin plate 23 to be measured by the flatness measuring device is mainly a substrate such as a metal plate, a ceramic plate or a resin plate, which is a material of a magnetic disk, in addition to a semiconductor wafer such as silicon. However, it is not limited to a disk-shaped or disk-shaped one such as a wafer, but may be a shape other than a circle. In short, as long as it is required to measure the degree of flatness, which is the degree of occurrence of uneven thickness or warpage, with high accuracy, it can be applied as a measurement object regardless of the material and the shape and dimensions.

At a position below the direct drive motor 1 on the upper surface of the apparatus base 20, a pair of guide rails 10 are provided.
Are installed in a direction parallel to the surface of the thin plate member 23 held by the direct drive motor 1, respectively. The moving stage 9 is slidably mounted on the upper portion of the moving stage 9 over both guide rails 10.
Driven by the two guide rails 1
It is moved linearly along 0.

The mounting base 27 of the pair of optical displacement gauges 3 has a rectangular appearance in this embodiment, and is arranged to surround the direct drive motor 1 and the thin plate 23 held by the direct drive motor 1. And is supported on the moving stage 9. The mounting base 27 is formed by joining lower end surfaces of both sides of a substantially inverted U-shaped reinforcing member 29 to upper end surfaces of both sides of a base portion 28 having a substantially U-shaped lower portion, and a substantially rectangular shape as a whole. It has an external shape. Base 2
Numeral 8 has a stable shape in which both side plate portions are widened downward, and the optical displacement gauges 3 are respectively attached to symmetrical positions of opposing surfaces near the upper ends of the both side plate portions. . Thereby, the pair of optical displacement meters 3
Are arranged at predetermined intervals with respect to the facing surface of the thin plate member 23 which is held vertically by the direct drive motor 1 and rotates. The optical displacement meter 3 measures the distance to the surface of the thin plate 23 or a change in the distance by irradiating the surface of the thin plate 23 with measurement light and receiving the measurement light reflected by the surface. is there. Details of the measuring operation by the optical displacement meter 3 will be described later.

Since the mounting table 27 has a rectangular appearance, the rigidity of the mounting table 27 is remarkably improved. The mounting position of the pair of optical displacement meters 3 is affected by the vibration from the vibration source. Is reduced. Further, the base portion 28 constituting the lower half of the mounting base 27 is formed of a stone material, and effectively absorbs and attenuates vibration caused by the rotation of the thin plate member 23 and the linear movement of the mounting base 27 itself. Can be done. Further, the reinforcing member 29 constituting the upper half of the mounting base 27 is formed of a lightweight material, for example, H-shaped steel while obtaining sufficient rigidity. As a result, the mounting base 27 has a relatively light overall weight due to the base portion 28 made of stone and the reinforcing member 29 made of H-shaped steel, and is driven by the rotation of the ball screw 8 by the relatively small motor 7. Since it can be moved at a high speed, it can be efficiently performed even when inspecting a large number of thin plate members 23.

FIG. 2 is an enlarged perspective view showing a state in which the thin plate member 23 is held by the thin plate member fixing unit 24, which is a constitution of the present invention. The thin plate fixing unit 24 has the following configuration. That is, the central portion of the movable portion 31 having a substantially U-shape in plan view is rotatably supported by the support base 30 fixed to the inner peripheral surface of the hollow spindle 2 via the support shaft 32. . A holding claw 3 having a V-shaped holding groove 34 with a groove depth of about 0.2 mm at the upper end is provided on the upper surface of one side (left side in the figure) of the movable portion 31.
3 is fixed in an upright state. On the other side (the right side in the figure) of the movable section 31, a counter balance section 37 is integrally formed. The movable portion 31 is moved in a direction in which the holding claw portion 33 is pushed upward by an extension spring 39 suspended between a mounting pin 38 protruding from the other end surface and the inner peripheral surface 2a of the hollow spindle 2 as shown by an arrow in the drawing. Is urged to rotate.

The counterbalance portion 37 has the same mass (rotational moment) as a mechanical portion required for holding the thin plate member 23 located at one end from the mounting portion of the support shaft 32 on the movable portion 31 including the holding claw portion 33. Is set to the mass of Therefore, when the thin plate member 23 is rotated at a high speed of about 240 rpm during measurement, the thin plate member fixing unit 24 has the same movable part 31 on both sides of the support shaft 32 which is an operation fulcrum. Since the centrifugal forces acting to rotate in the opposite directions act on each other, the centrifugal forces on both sides are canceled each other.

That is, the centrifugal force acting on the mechanical portion on the holding claw portion 33 side with respect to the support shaft 32 in the thin plate fixing unit 24 is canceled by the centrifugal force acting on the counter balance portion 37. Therefore, regardless of the action of the centrifugal force generated during high-speed rotation, a constant pressing force set by the spring force of the tension spring 39 is applied to the holding claw 33 without any change, and the holding claw 33 is thinned by the holding groove 34. Plate 23
Keeps the outer peripheral edge portion stable. Thus, the thin plate member 23 is always held at the three outer peripheral edges with a predetermined holding force even at the time of high-speed rotation, and is not distorted. As a result, it is possible to efficiently measure the warpage of the thin plate 23 by the optical displacement meter 3 with extremely high measurement accuracy.

In this embodiment, the actuator 40 composed of an air cylinder or the like for releasing the holding of the thin plate 23 in the thin plate fixing unit 24 is provided.
The movable rod 31 is fixed to the exterior fixing part 22 of the direct drive motor 1 in such a manner that the operating rod 40a faces a passive pin 41 protruding from the other end of the movable part 31. That is,
Since the direct drive motor 1 stops with the hollow spindle 2 at a specific position, the actuator 40
Is mounted so that the operating rod 40a is positioned so as to exactly face the passive pin 41 when the hollow spindle 2 stops. This actuator 40
When the rotation of the hollow spindle 2 is stopped after the measurement of the entire surface of the thin plate member 23 is completed, the passive pin 41 is pushed up by the ejected operating rod 40 a to rotate the movable portion 31, thereby holding the holding claw. The holding of the thin plate member 23 by the holding groove 34 of the portion 33 is released. Therefore, the actuator 40 is fixed independently of the thin plate fixing unit 24 at the time of measurement by rotation of the thin plate 23, and the rotational load of the direct drive motor 1 can be reduced.

FIG. 3 is a perspective view showing a thin plate fixing unit 42 in a flatness measuring apparatus for a thin plate 23 according to another embodiment of the present invention. The overall configuration of the flatness measuring device for the thin plate 23 is almost the same as that of FIG. 1 except for the thin plate fixing unit 42. In the thin plate fixing unit 42, the unit base 43 is placed on the inner peripheral surface 2 a of the hollow spindle 2 and fixed to the side surface of the hollow spindle 2 by screws 44. A fixing mechanism 47 is installed at the center, and a pair of mounting guide mechanisms 48 are installed in close proximity to both sides of the fixing mechanism 47. FIG.
6A is a longitudinal sectional view of the fixing mechanism 47 taken along the longitudinal direction, and FIG. 6B is a longitudinal sectional view of the mounting guide mechanism 48 taken along the longitudinal direction.

The fixing mechanism 47 is shown in FIGS. 3 and 4 (a).
As shown in FIG. 5, a main body block 49 formed of a hard resin or the like, and a holding claw portion 5 fixed to the upper surface of one end (the left end in each drawing) of the main body block 49 and holding the thin plate material 23
0, a tension spring 51 for applying a holding force to the thin plate member 23 to the holding claw portion 50, and a solenoid 52 of a rotary drive source for releasing the holding of the thin plate member 23 by the holding claw portion 50. It is configured.

In the main body block 49, horizontal hollow grooves 53 are formed at both sides in the longitudinal direction at the center part in the thickness direction, and the support base 57 below the hollow groove 53 and the upper movable part 58 are integrated. And has a hollow 53
The central portion in the longitudinal direction that is left without being formed is a rotation fulcrum 54 having elasticity. The main body block 49
The support base 57 is fixed to the unit base 43 by screws 59, and the movable part 58 is rotatable to both sides with the rotation fulcrum 54 as a fulcrum. The tension spring 51 is suspended between the other end (the right end in each figure) of the main body block 49 and the unit base 43, and supports the holding plate 50 in the direction of pushing up the holding claw 50, that is, supports the thin plate member 23 with the holding groove 50a. The movable portion 58 is urged to rotate in the direction. On the other hand, the solenoid 52 connected to one end of the movable portion 58 operates (generally sucks).
As a result, the movable portion 5 is moved in a direction in which the holding claw 50 is pulled down, that is,
8 is rotated.

The holding claw 50 fixed to one end of the movable portion 58 has a groove depth of 0.2 m similar to that formed on the holding claw 33 of the thin plate fixing unit 24 in one embodiment.
It has a V-shaped holding groove 50a of about m, and the thin plate 23 is held by inserting the outer peripheral edge of the thin plate 23 into the holding groove 50a. At the other end of the movable portion 58, a counter balance portion 60 is integrally formed in a hanging state.
4 is set to have the same mass on both sides.

On the other hand, the mounting guide mechanism 48 disposed close to both sides of the fixing mechanism 47 has a main body block 61 having the same configuration as the main body block 49 of the fixing mechanism 47. However, the main body block 61 is disposed with the longitudinal direction thereof reversed with respect to the main body block 49 of the fixing mechanism 47. Accordingly, the main body block 61 is integrally provided with two hollows 62, a rotation fulcrum 63, a support base 64, a movable part 67, and a counter balance part 68, similar to the main body block 49. Is a screw 6
9 is fixed to the unit base 43.

At one end (left end in the figure) of the movable portion 67,
Guide pieces 70 each having a tapered guide face 70a as shown in FIG. 3 are fixed to each other, and the pair of guide pieces 70 are opposite to each other with the respective guide faces 70a facing each other toward the holding claw 50. It is fixed in the arrangement of. Movable part 67 that is rotatable about rotation fulcrum 63
Is always urged by a tension spring 71 suspended between one end thereof and the unit base 43 in a direction in which the guide piece 70 is pulled down, and the other end (the right end in the figure) is connected. When the solenoid 72 is actuated (generally sucked), the guide piece 70 is rotated in the upward direction.

The movable section 58 of the fixed mechanism section 47
The rotation range in both directions is regulated by movable limit members 73 provided at symmetrical positions on both sides of the rotation fulcrum 54. Similarly, the mounting guide mechanisms 4 on both sides
In the movable portion 67 in FIG. 8, the range of rotation in both directions is regulated by the movable limit members 74 provided at symmetric positions of the rotation fulcrum 63. Movable limit member 7
4 is made of a non-dusting material, for example, Teflon, in order to minimize contamination of the thin plate material 23 such as a semiconductor wafer to be measured with dust.

Next, the thin plate fixing unit 42
Will be described with reference to the operation explanatory diagram of FIG. In addition, two thin plate fixing units other than the thin plate fixing unit 42 (hereinafter, referred to as an example unit) shown in FIGS. 3 and 4 are provided with the holding claw 50 in a fixed manner. After the outer peripheral edge of the thin plate 23 is fitted into the holding groove 50 a of the unit 42, the thin plate 23 is pressed and displaced by the holding claw 50 to fix the other two outer peripheral ends of the thin plate 23. The thin plate 23 is sandwiched by being inserted into the holding grooves of two holding claws provided in a special manner. However, in FIG. 5, for convenience of explanation, the thin plate fixing unit 4 shown in FIGS. 3 and 4 is used.
2 illustrates a configuration provided with a movable holding claw portion 50 similar to that of FIG. In addition, the three thin plate fixing units 42
Have a pair of movable guide pieces 70 similar to each other.

First, when attaching the thin plate members 23 to the three thin plate fixing units 42 of the hollow spindle 2, as shown in FIG. The handling arm 77 of (3) grasps three equally-spaced outer peripheral edges of the thin plate material 23. The gripping of the sheet material 23 by each handling arm 77 is performed in a state where the outer peripheral edge of the sheet material 23 is inserted into the V-shaped holding groove 77a of each handling arm 77, and the sheet material 23 is sandwiched. Handling arm 77 holding this thin plate 23
Is transported from the outside into the hollow spindle 2 and stopped in a state where the thin plate member 23 is positioned at a predetermined position in the center of the hollow spindle 2.

When the thin plate member 23 is carried into the hollow spindle 2, the solenoid 52 is energized in the fixing mechanism 47 so that the movable part 58 is rotated counterclockwise in FIG. The portion 50 is retracted to a position outside the mounting position of the thin plate member 23 so as not to hinder the carrying in of the thin plate member 23. In addition, in the mounting guide mechanism 48 on both sides,
When the solenoid 72 is in the non-energized state, the movable portion 67 is rotated counterclockwise in FIG. 4B by the urging force of the tension spring 71, and the guide piece 70 is moved outside the mounting position of the thin plate member 23. It is retracted to a position where it does not hinder the loading of the sheet material 23.

Next, in the mounting guide mechanism section 48 on one side (left side in FIG. 3), the movable section 67 is rotated clockwise in FIG. As shown by an arrow in FIG.
Is advanced toward the inner side of the hollow spindle 2. At this time, the thin plate member 23 contacts the inner surface of the guide piece 70 while the guide surface 70a of the guide piece 70 that advances inward slides even if there is a warp to the left in the drawing. By being guided to perform, the shape is corrected so as to eliminate the warpage or the like.

Subsequently, in the mounting guide mechanism section 48 on the other side (right side in FIG. 3), the movable section 67 is rotated clockwise in FIG. As shown by an arrow in FIG.
Is advanced toward the inner side of the hollow spindle 2. At this time, the thin plate member 23 contacts the inner surface of the guide piece 70 while the guide surface 70a of the guide piece 70 that advances inward slides even if there is a warp to the right in the drawing. By being guided to perform, the shape is corrected so as to eliminate the warpage or the like.

By the above operation, the thin plate member 23 is sandwiched by the pair of guide pieces 70 at the three outer peripheral edges while being sandwiched by the three handling arms 77, and the outer peripheral edge is held by each of the holding claws. The shape is corrected so as to exactly face the holding groove 50a of the 50. Thereafter, in the fixing mechanism 47, the energization of the solenoid 52 is stopped, and the movable part 58 is moved by the urging force of the tension spring 51 in FIG.
By being rotated clockwise in FIG. 5A, FIG.
As shown by the arrow in FIG.
It is advanced toward the inside of. At this time, since the outer peripheral end of the thin plate member 23 is accurately opposed to the holding groove 50a of the holding claw 50 as described above, the inside of each holding groove 50a of the holding claw 50 that protrudes inward is set. The opposed outer peripheral edges of the thin plate 23 are securely inserted, and the thin plate 23 is sandwiched by the three holding claws 50. Therefore, in this thin plate fixing unit 42, the extremely thin thin plate 23 having a thickness of 0.775 mm can be reliably inserted into the holding groove 50a having a groove depth of 0.2 mm, and the thin plate 23 can be thinned like the conventional device. Plate 23
However, troubles such as falling due to failure of holding will not occur.

When the holding and fixing of the thin plate 23 by the holding grooves 50a of the three holding claws 50 are completed, each handling arm 77 releases the holding of the thin plate 23 and then moves in the direction of the arrow shown in FIG. And retracts to the outside of the hollow spindle 2. At the same time, in the mounting guide mechanisms 48 on both sides, the energization of the solenoid 72 is stopped, and the movable portion 67 is rotated counterclockwise in FIG. The guide piece 70 retreats outward from the outer peripheral end of the thin plate member 23 as shown in FIG.

By the above operation, the attachment of the thin plate 23 to the thin plate fixing unit 42 is completed, the direct drive motor 1 starts rotating, and the thickness of the thin plate 23 by the optical displacement meter 3 is reduced. A measurement is taken. During this measurement operation, the solenoid 52 of the fixed-side mechanism 47 and the solenoids 72 of the mounting guide mechanisms 48 on both sides are in a non-energized state, and the holding claw 50 is connected to the thin plate 23 by the tension spring 51. The guide pieces 70 are urged in the pressing direction, and the respective guide pieces 70 are held at the retracted positions on the outer side of the thin plate member 23 by the urging forces of the tension springs 71, respectively. As described above, the solenoids 52 and 72 that rotate together with the thin plate member 23 are de-energized at the time of rotation to eliminate the possibility of dust generation.

Further, in the direct drive motor 1, since the hollow spindle 2 stops at a specific position, the electrodes for energizing the solenoids 52 and 72 are arranged near the stop position of the thin plate fixing unit 42. And
When the solenoids 52 and 72 are energized, the solenoids 52 and 72 are brought into electrical contact with each other by an automatic connection device.

When the thin plate 23 is rotated at a high speed of about 240 rpm when measuring the thin plate 23, the fixing mechanism 47
The centrifugal force acts on both sides of the rotation fulcrum part 54 of the movable part 58 of the movable part 58. Since the mass of the both sides is set to be the same by the counter balance part 60, the centrifugal force acting on the both sides is Since the forces are the same and are in the directions to rotate in opposite directions,
Mutually defeated. Therefore, regardless of the effect of the centrifugal force generated during high-speed rotation, the holding claw portion 50 is provided with a constant pressing force set by the spring force of the tension spring 51 without constantly changing, and the holding claw portion 50 is thinned by the holding groove 50a. Plate 2
3 is stably held. Thus, the thin plate member 23 is always held at the three outer peripheral edges with a predetermined holding force even at the time of high-speed rotation, and is not distorted. As a result, it is possible to efficiently measure the warpage of the thin plate 23 by the optical displacement meter 3 with extremely high measurement accuracy.

The centrifugal force also acts on both sides of the rotating fulcrum 54 in the movable portion 67 of the mounting guide mechanism 48 on both sides, and the mass of the both sides is made equal by the counter balance portion 68. Since it is set, the centrifugal forces acting on both side portions are the same and are in the directions of rotating in opposite directions, and therefore cancel each other. Therefore, regardless of the action of centrifugal force generated during high-speed rotation, the guide piece 70
The constant tensile force set by the spring force is always applied without any change, and the retracted state is reliably held at a position where it does not hinder the rotation of the thin plate member 23.

The thin plate fixing unit 42 has a fixing mechanism 47 for holding the thin plate 23 and a pair of mounting members disposed on both sides thereof for performing an auxiliary operation for securely holding the thin plate 23. Despite having the guide mechanism 48, each of the mechanisms 47, 48 is supported by the support bases 57, 6
4. Since the main body blocks 49 and 61 are provided integrally with the movable parts 58 and 67, the pivot points 54 and 63, and the counter balance parts 60 and 68, the number of parts can be reduced as much as possible. It has a very simplified configuration.

In the above embodiment, the pair of mounting guide mechanisms 48, 48 are provided on the inner peripheral surface of the hollow spindle 2 and are rotated integrally with the thin plate member 23. The parts 48, 48 may be provided on the exterior fixing part 22 so that the guide piece 70 is advanced so as to be brought into contact with the thin material 23 carried into the hollow spindle 2 only when the thin material 23 is attached.

Next, measurement of the flatness of the thin plate 23 by the optical displacement meter 3 in each of the above embodiments will be described. FIG. 6 is an overall configuration diagram showing a measurement mechanism unit using the optical displacement meter 3 in the flatness measurement device for the thin plate member 23 of each of the above embodiments. In the same figure, a pair of optical displacement gauges 3 arranged on both sides of a thin plate material 23 are:
Each of them has a measuring optical system 78 and a light receiving section 79 and operates with laser light output from one laser output device 80. As the laser output device 80, a frequency-stabilized He-He laser is used.
From 0, the mixed light L ₀ + L of the reference light L ₀ and the measurement light L _1
1 is output. This mixed light L ₀ + L ₁ passes through a plurality of mirrors 81 and isolators 82 and is split in two directions by a beam splitter 83. Divided mixed light L ₀ +
L ₁ is further supplied to the measurement optical systems 78 on both sides of the thin plate member 23 via a plurality of mirrors 81. Note that the internal configuration of the measurement optical system 78 on the right side of the figure is the same as that on the left side, and is not shown.

In the measuring optical system 78, the mixed light L ₀ + L
_{After 1} is narrowed down by the converging lens 84, it is supplied to a polarization beam splitter 87 serving as a branching / mixing unit. The converging lens 84 narrows down the mixed light L ₀ + L ₁ , so that the measuring light L ₁ is accurately converged on the surface position of the thin plate member 23 and radiated. However, in this embodiment, the light is not converged directly on the surface of the thin plate member 23, but is converged on the reflection surface of the stylus reflector 88. In the polarization beam splitter 87,
The measurement light L ₁ is straight as it is, the reference light L ₀ is branched so as to reflect perpendicularly. Such branching is caused by the polarization direction difference between the measurement light L ₁ to be output by the laser output device 80 and the reference light L _0.

After passing through the λ / 4 wavelength plate 89, the measuring light L ₁ travels toward the surface of the thin plate 23. Stylus reflector 88 on the surface of the thin plate member 23 is in contact with the measurement light L ₁ is reflected by a probe reflector 88, polarizing beam splitter 8 again
It is returned to 7. The reference light L ₀ exiting the polarization beam splitter 87 passes through the λ / 4 wavelength plate 90, is reflected by the reference mirror 91, and returns to the polarization beam splitter 87 again. The distance from the polarization beam splitter 87 to the reference mirror 91 depends on the distance from the polarization beam splitter 87 to the stylus reflector 8.
The distance is set to be the same as the distance up to 8.

The λ / 4 wavelength plate 9 reflected by the reference mirror 91
The reference light L ₀ that has passed through the polarization beam splitter 87
Go straight on. The measurement light L ₁ will proceed in the same direction as the reference light L ₀ is reflected at a right angle by the polarization beam splitter 87. As a result, from the polarization beam splitter 87,
Mixed light L ₀ + L ₁ and reference light L ₀ and the measurement light L ₁ is outputted. However, the stroke of light until then, depends distance to the surface of the measurement light L ₁ at probe reflector 88 until the distance, that the thin plate 23, does not change the reference light L _0,
A stroke difference or a phase difference occurs between both lights.

The mixed light L ₀ + L ₁ output from the polarization beam splitter 87 passes through a plurality of mirrors 92, a collimator lens 93 and a focus lens 94, and passes through a light receiving section 7.
9 is input. The collimating lens 93 outputs the mixed light L ₀
+ L ₁ is made parallel light, and the focus lens 94 is
The ₀ + L ₁ is converged on the light receiving surface of the light receiving unit 79, the measurement light L
_The inclination and the displacement caused by the reflection of _{1 on} the surface of the thin plate member 23 are corrected, and the light is surely input to the light receiving surface of the light receiving section 79.
The light receiving unit 79 converts the optical signal into an electric signal, or electrically analyzes the wavelength and phase of the reference light L ₀ and the measurement light L ₁ , and performs an arithmetic processing on the data so that the data can be processed up to the surface of the thin plate material 23. Is obtained as numerical information. Reference light L
₀ and by causing interference measurement light L _1, if ask to appear by expanding or clarify the difference of the above-described stroke or phase as interference fringes, warpage and thickness of the surface of the thin plate 23 in the photoelectric conversion element Information such as unevenness is easily extracted as an electric signal.

By moving the pair of optical displacement gauges 3 linearly along the rotation radius of the thin plate 23, the above-described measurement is repeated while changing the measurement position with respect to the surface of the thin plate 23. Is required to determine the presence or absence of surface irregularities, that is, the flatness. That is, the thin plate material 2
The sum of the information measured by the pair of optical displacement gauges 3 disposed on both sides of the surface 3 indicates a change in the thickness of the thin plate member 23, that is, warpage or uneven thickness. In the measurement of warpage and uneven thickness, it is not necessary to measure the thickness of the thin plate material 23 itself, and the difference or variation in thickness in the plane direction may be measured as warpage or uneven thickness. If the distance between the displacement gauges 3 is known, the sheet material 2 for both
The thickness of the thin plate 23 can be known from the measurement information of No. 3.

FIG. 7 is a schematic diagram for explaining the measuring operation on the thin plate 23. Next, a method for measuring the surface displacement of the entire thin plate 23 by the optical displacement meter 3 based on the drawing. Will be described. The sheet material 23 is rotated in one direction in a vertical plane. On the other hand, the optical displacement meter 3 measures the surface displacement of the thin plate 23 while being moved in the radial direction from the outer periphery A of the circular plate 23 toward the center B. As a result, the position of the optical displacement meter 3 is
Moves along the spiral line indicated by the locus S. If the surface displacement of the thin plate 23 is measured by the optical displacement meter 3 at appropriate intervals on the trajectory S, the surface displacement over the entire surface of the thin plate 23 can be efficiently measured. The optical displacement meter 3 has a linearly linear radius AB in the horizontal direction.
, The operation mechanism of the optical displacement meter 3 is simplified. The measurement of the surface displacement with respect to the thin plate 23 may be performed after the rotation of the thin plate 23 is started and the rotation speed is constant, but the method described below is more efficient.

FIG. 8A is an operation diagram showing a change in the rotational speed (angular speed ω) of the thin plate 23 in one measurement tact, and FIG. 8B shows a change in the linear moving speed Vx of the optical displacement meter 3. FIG. When the thin plate 23 held by the hollow spindle 2 is rotated by the motor 1, the thin plate 2
3 and the rotating member of the hollow spindle 2 have a moment of inertia, so that the rotation speed cannot be set to the predetermined rotation speed immediately at the start of rotation, and the rotation speed ω gradually increases from the state of the rotation speed ω = 0, and becomes constant. After a certain time, the predetermined rotational speed is reached. When the rotation is stopped at the end of the measurement, the rotation speed ω gradually decreases and returns to 0 after a certain period of time and stops. Similarly, the speed of the linear displacement of the optical displacement meter 3 gradually increases from the state of the speed Vx = 0 at the start of the movement. At the end of the movement, the speed Vx gradually decreases and returns to zero.

Therefore, conventionally, the measurement is performed only while the rotational speed ω of the thin plate member 23 is constant, but the acceleration time before the start of the measurement and the deceleration time after the end of the measurement are different from the original measurement time. Others are required, and the measurement tact becomes longer. When the measurement is performed after the rotation speed ω of the thin plate 23 becomes a constant speed, the acceleration time until the rotation speed ω of the thin plate 23 reaches a certain speed from the stop state becomes a time where the measurement cannot be performed. Naturally, the measurement tact time is extended accordingly. Therefore, in the method shown in FIG. 8, the linear displacement of the optical displacement meter 3 is started simultaneously with the start of the rotation of the thin plate member 23, and the displacement measurement (data acquisition) by the optical displacement meter 3 is also started. At this time, the rotation speed of the thin plate member 23 and the moving speed of the optical displacement meter 3 gradually increase.

The rotational speed of the thin plate 23 and the linear moving speed or moving position of the optical displacement meter 3 are detected by a sensor such as a rotary encoder or a position sensor, and are processed by a calculating means such as a microcomputer. If the operation of the thin plate 23 and the optical displacement meter 3 is synchronized by controlling the direct drive motor 1 and the motor 7 on the basis of the direct drive motor 1 and the motor 7, the thin plate 23 is moved along the spiral locus S shown in FIG.
And the optical displacement meter 3 can be relatively moved. The displacement is measured by the optical displacement meter 3 for each predetermined position set on the trajectory S.

As shown in FIG. 8B, the optical displacement meter 3
However, the moving speed Vx is accelerated until the distance from the outer circumference A to the middle of the radius AB, and a constant speed (for example, Vx = 8 mm)
/ Sec), the vehicle immediately accelerates and stops at the center position B. There is no need to maintain a constant speed. FIG.
As shown in (a), the rotation speed ω of the thin plate member 23 accelerates from the start of rotation to the peak of the moving speed Vx of the optical displacement meter 3 and reaches a maximum speed (for example, ω = 240 rpm). After that, the rotation is stopped at the same time as the stop of the optical displacement meter 3 by decelerating from the peak time. By performing the above-described operations, measurement tact can be significantly reduced as compared with a method in which measurement is started after a certain speed is reached, measurement is completed, and deceleration is stopped.

In the above-described embodiment, the case where the distance to the facing surface of the thin plate or the change in the distance is measured by the optical displacement meter 3 has been described as an example. However, a stylus type or capacitance type displacement sensor is used. The effect of improving the measurement accuracy can be obtained even if is used.

[0064]

As described above, according to the method for measuring the flatness of a thin plate material according to the present invention, the thin plate material carried into the mounting position in the hollow spindle is held by the holding claws of the plurality of thin plate fixing units. At the time of holding, the pair of guide pieces are advanced toward the mounting position and brought into contact with both sides of the thin sheet material, so that even if the thin sheet has a warp, the thin sheet material is eliminated so as to eliminate the warp etc. Can be corrected, and even if the sheet material is extremely thin, it can be reliably held by the holding claws. Further, since the thin plate rotating means is driven while maintaining the balance so that the mass of the both sides of the rotating fulcrum part in the movable part is the same, the two sides of the movable part with respect to the rotating fulcrum part are respectively provided. The centrifugal forces acting on each other can be canceled each other, and the thin plate can always be held at a predetermined holding force without distortion even during high-speed rotation. Can be measured.

According to the apparatus for measuring flatness of a thin plate material of the present invention, a thin plate fixing unit for holding the thin plate material in the hollow spindle is provided with a holding claw portion at one end side from a rotation fulcrum portion of the movable portion. Since the counterbalance portion having the same mass as the mass of the thin plate holding mechanism portion including the thin plate material is provided at the other end of the movable portion, both sides of the rotating fulcrum portion of the movable portion when the hollow spindle rotates. Since the centrifugal forces generated in the portions can be canceled each other, even when the thin plate material is rotated at high speed, the holding claw portion is set by the elastic body regardless of the action of the centrifugal force generated at high speed rotation. A constant urging force is applied without any change, and the holding groove keeps holding the thin plate material stably. Accordingly, the thin sheet material is always held at a predetermined holding force even at the time of high-speed rotation and is not distorted. Therefore, the displacement meter measures the warp or the thickness unevenness of the thin sheet material efficiently with extremely high measurement accuracy. be able to.

Further, when the sheet material is carried into the mounting position with a tapered guide surface at the end of the opposing surface, the thin plate is advanced toward the mounting position before the holding claw advances to the mounting position. When a pair of guide pieces are arranged close to both sides of the holding claw portion, the thin plate material is sandwiched between the pair of guide pieces, and the outer peripheral end is accurately opposed to the holding groove of each holding claw portion. Can be modified. As a result, a very thin sheet material having a thickness of 1 mm or less can be reliably inserted into the holding groove having a groove depth of 1 mm, and the trouble that the thin sheet falls due to failure of holding as in the conventional apparatus can be avoided. Occurrence can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an apparatus for measuring flatness of a thin plate material according to an embodiment embodying the method of measuring flatness of a thin plate material according to the present invention.

FIG. 2 is an enlarged perspective view showing a fixed state of the thin plate material by a fixing unit in the thin plate flatness measuring device of the above.

FIG. 3 is a perspective view showing a fixing unit as a main part in a flatness measuring apparatus for a thin plate according to another embodiment of the present invention.

FIG. 4A is a longitudinal sectional view of a fixing member of the same fixed unit, and FIG. 4B is a longitudinal sectional view of a guide member of the same fixed unit.

FIGS. 5A to 5D are explanatory views of the operation of the thin plate fixing unit according to the first embodiment.

FIG. 6 is an overall configuration diagram showing a measuring mechanism in the thin plate flatness measuring device of the above.

FIG. 7 is a schematic diagram for explaining a measuring operation on the thin plate material in the thin plate flatness measuring apparatus according to the first embodiment.

FIG. 8 is an operation diagram showing time-dependent operations of the thin plate and the optical displacement meter in the thin plate flatness measuring device of the above.

FIG. 9 is a perspective view showing a conventional flatness measuring apparatus for a thin plate material.

FIG. 10 is a perspective view showing a holding state of a thin plate material by a fixing unit in the flatness measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Direct drive motor (thin plate rotating means) 2 Hollow spindle 3 Optical displacement meter (displacement sensor) 9 Moving stage (measurement scanning means) 23 Thin plate 24, 42 Thin plate fixing unit 30 Support base (support) 31 , 58 Movable part 32 Support shaft (rotation fulcrum part) 33, 50 Holding claw part 34, 50a Holding groove 37, 60 Counter balance part 39, 51 Tension spring (elastic body) 47 Fixing mechanism part 48 Mounting guide mechanism part 49 Fixing Main body block of the mechanical part 52 Solenoid of the fixing mechanism part 54 Rotating fulcrum part 61 Main body block of the mounting guide mechanism part 63 Rotating fulcrum part of the mounting guide mechanism part 64 Support base (support part of the mounting guide mechanism part) 67 Mounting guide Movable part of mechanism part 68 Counter balance part of mounting guide mechanism part 70 Guide piece 70a Guide surface 71 Tension spring Mounting guide mechanism portion of the elastic member) 72 attached guide mechanism portion of the solenoid

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Mochizuki 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (72) Inventor Hiroyuki Takeuchi 1006 Odaka Kazama Kadoma, Osaka Pref. 72) Inventor Koji Handa 1006 Kadoma, Kazuma, Osaka Pref.F-term in Matsushita Electric Industrial Co., Ltd. BB15 BB17 CC07 DD15 DD16 DD25 GG01 GG04 GG06 GG07 GG58 GG63 HH09 HH30 JJ06 JJ13 JJ17 JJ25 MM02 MM26 PP01 3C029 BB01

Claims (4)

[Claims] 1. A thin sheet material carried into a mounting position inside a hollow spindle in a thin sheet material rotating means is separated from a plurality of thin sheet fixing units disposed on an inner peripheral surface of the hollow spindle by a pair of guide pieces. Each of the thin plate fixing units is advanced to the mounting position and is brought into contact with one surface and the other surface of the outer peripheral edge of the thin plate to be positioned at a predetermined position. By rotating the movable part in one direction by applying elastic force, the outer peripheral edge of the thin plate material is held by the holding claw part of the movable part that advances between the pair of guide pieces, Thereafter, the pair of guide pieces are retracted in a direction away from the thin plate material, and the thin plate material is attached to an inner peripheral surface of a hollow spindle via a plurality of the thin plate fixing units, and is attached to the movable portion. The thin plate is rotated by driving the thin plate rotating means while maintaining a balance so that the mass of both sides of the rotating fulcrum portion is the same, and the symmetrical position of the thin plate on both sides. While measuring the distance to the opposing surface of the thin plate material by a pair of displacement sensors arranged in, and scanning the measurement position of the pair of displacement sensors in the rotational radius direction of the thin plate material, the pair of displacement sensors Measuring the distance or change in the distance to the entire surface of the thin plate, and calculating thickness unevenness and warpage over the entire surface of the thin plate based on each measurement data of the pair of displacement sensors; Flatness measurement method. 2. A thin plate rotating means for rotating a thin plate while holding it in a hollow spindle, and fixing a plurality of thin plates fixed to an inner peripheral surface of the hollow spindle and holding an outer peripheral edge of the thin plate. A pair of displacement sensors disposed at symmetrical positions on both sides of the thin plate material to measure a distance or a change in distance to an opposing surface of the thin plate material, and a measuring position of the displacement sensor to the thin plate material. Measurement scanning means for scanning the plate material in the radial direction of rotation, and flatness calculation means for calculating thickness unevenness and warpage over the entire surface of the thin sheet material based on each measurement data of the pair of displacement sensors, at least One of the thin plate fixing units includes a support portion fixed to an inner peripheral surface of the hollow spindle, and a central portion rotatably provided by being supported by the support portion via a rotation fulcrum. A movable portion, a holding claw provided at one end of the movable portion with a holding groove for fitting and holding an outer peripheral edge of the thin plate, and pressing the holding claw against the thin plate. An elastic body for urging the movable portion to rotate in the direction,
A counter balance part provided at the other end of the movable part and having the same mass on both sides of the rotation fulcrum part in the movable part. Flatness measuring device for thin materials. 3. The thin plate fixing unit includes a pair of guide pieces disposed close to each other on both sides of the holding claw portion, and the pair of guide pieces is provided at a tip end of each of the opposing surfaces. A tapered guide surface, when the thin plate material is carried into a predetermined mounting position in the hollow spindle, the thin plate material is advanced toward the mounting position before the holding claw portion advances to the mounting position; The flatness measuring device for a thin plate material according to claim 2, wherein the flatness measuring device is configured to be in contact with one surface and the other surface of the outer peripheral edge portion of the thin plate material. 4. A thin plate fixing unit comprising: a fixing mechanism having a holding claw at one end; and a mounting guide mechanism having a guide piece at one end disposed close to both sides of the fixing mechanism. The mechanism section includes a main body block in which a support section, a pivot point, a movable section, and a counter balance section are integrally formed,
A holding claw portion fixed to one end of the movable portion, an elastic body for urging the movable portion to rotate in a direction to cause the holding claw portion to advance to the mounting position of the thin plate material, and the holding claw portion being attached to the mounting position. A solenoid for rotating the movable portion in a direction to retract from the support portion, wherein each of the mounting guide mechanism portions includes a support portion fixed to a hollow spindle, and a support portion having a central portion via a rotation fulcrum portion. And a counter provided at the other end of the movable portion and having the same mass on both sides with respect to the rotation fulcrum of the movable portion. A guide block fixed to one end of the movable section, and the movable section is rotated in a direction in which the guide section advances to a mounting position of the thin plate material. Solenoid and guide piece The flatness measuring apparatus for a thin plate material according to claim 3, further comprising: an elastic body that urges the movable portion to rotate in a direction to retract from the mounting position.